If your magento's cache is enable and for particular section your dynamically content not reflect and remains same for every category or product page use following code.
<?php Mage::app()->saveUseCache('block_html'); ?>
If you just need to refresh one type, Bock Html OutPut for instance, you just need to use this :
$type= "block_html";
Mage::app()->getCacheInstance()->cleanType($type);
That's it. Hope it will help you :)
